1. Field
One or more embodiments of the present invention generally relates to a focusing method, medium and apparatus for focusing sound to a particular position, and more particularly, to a method and apparatus for focusing sound to a position located a predetermined distance from and in a predetermined direction relative to an array speaker system composed of a plurality of speakers by adjusting a sound signal using the array speaker system.
2. Description of the Related Art
An array speaker system is composed of a plurality of speakers that can adjust the direction of reproduced sound or radiate sound towards a particular area. The principle of sound transmission, generally called directivity, is to make a plurality of sound source signals overlap each other using phase differences between the sound source signals in order to increase signal strength along a specific direction, thereby transmitting the sound source signals in the specific direction. Thus, such directivity can be implemented by disposing a plurality of speakers in particular positions and adjusting the sound source signals of the array, which are output through the speakers.
As various portable digital devices have come into common use, the need for speakers capable of reproducing sound signals has increased. Along with this trend, users' expectation levels and demands with respect to a sound reproduction function implemented in a portable digital device also gradually increase. For example, users demand speakers with increasingly sophisticated technology that have evolved from conventional mono speakers to stereo speakers and further to multi-channel array speakers. In particular, as devices which allow a user to listen to sound while carrying, such as miniaturized digital devices including a digital multimedia broadcasting (DMB), a portable multimedia player (PMP), and a video-conference portable phone, have recently come into wide use, a focusing technique for focusing sound to a particular position desired by the user using an array speaker system is required for sound listening.